On a parking area, the rotorcraft is subjected to weather conditions and more particularly to wind that can sometimes be violent.
The rotors of most modern rotorcrafts are equipped with blades that are flexible. As a result, while camping, such blades can start flapping vertically under the action of the wind.
This phenomenon lies behind many problems:                personnel working on the ground can be injured by a blade moving suddenly downwards;        when the blades are fitted with flapping hinges and bottom abutments, then during wind-driven vertical movements, the hinges and the abutments are subjected to high levels of force that can damage them in the long run;        depending on the locations of the blades, they can be blown by the wind so as to come into contact with structural elements of the rotorcraft, thereby leading to severe damage; and        finally, a rising blade can cause the rotorcraft to be turned over.        
A first known solution consists in a sock which covers the tip cap of a blade. A cord secured firstly to the sock and secondly to the structure of the rotorcraft, limits movements of the blade. Nevertheless, it is not unusual for socks to become deformed or to separate from the tip cap under wind forces.
A second known solution consists in a support permanently secured to the blade tip cap and in a removable endpiece which is connected to said support when lashing down. The blade is held by tensioning the cord between said endpiece and an anchor point provided on the structure of the rotorcraft. Those systems have the advantage of never coming undone.
Nevertheless, in both of the above-mentioned solutions, keeping the blades in a low position induces high levels of force on the anchor points of the rotorcraft. That means that the anchor points must be overdimensioned in order to be able to withstand high levels of force, and that is extremely penalizing, particularly in terms of cost and weight.
Furthermore, it is sometimes difficult to position the rotor blades so that they are in register with the anchor points, for example a blade might overlie the tail boom or the nose of the rotorcraft. Personnel in charge of lashing down then look for anchor points other than those initially provided, and that can lead to damage to the structure.